Bloodstain Patterns, Essay Example

Bloodstain Patterns- Area of Convergence and Area of Origin

Area of Convergence is defined as the area at a crime scene where lines which are two dimensional in nature, and have been drawn through the long axis of at least two individual bloodstains intersect away from the location of the blood source. While in terms of the Area of Origin, it is the three dimensional location from which a blood spatter had originated (Hemospat, 2012).

Investigators to a crime scene are able to use the two and three dimensional measurements provided by these two constructs, to determine successfully the direction of blood flow as well as the exact location of the crime, and then be able to re-construct the crime as it actually happened.

Information obtained from the crime scene, including those involving Area of Convergence and Area of Origin, are often invaluable to prosecutors in courtroom trials in their quest to bring accused to justice.

Determination of the Area of Convergence and the Area of Origin

The area of Convergence is determined by drawing lines from two elliptical blood stains on the floor from the center of the long axis of these stains in the direction of the blood flow until they meet at a specific point. This area, according to Forensic Investigators (2005), is also called the Point of Convergence, should always be constructed by working from the back of the bloodstains found at any crime scene

Calculating the Area of Origin is done by measuring the distance from the back end of a blood stain used to establish the Area of Convergence and calling this A. This should be followed by measuring the length and width of the same sample of blood stain and using the Law of Tangents with both to find the Angle of Impact (theta).

Using the Angle of Impact (Theta) and the length of the blood stain (H) in the tangential equation, the height at which the wound occur from above ground is then calculated.

Forensic Investigators can then determined the Area of Origin by then connecting the hypotenuse side of the equation to this specific height to complete his or her work, before moving to other analyses that will help to determine how the crime occurred and who committed it?

Reference

Forensic Investigations (2005). Blood Spatter – Properties of Blood www.cit.uwa.edu.au/_data/page/112508/FSB05.pdf , 09/12/12

The Association of Bloodstain Pattern Analyst (2012). Blood Spatter Terminology www.azflse.org/download.cfm?filename=BLOODSPATTERVOCABULARY&type=pd&loc=csiarizona , 09/12/12

Hemospat (2012). Bloodstain Pattern Analysis Terminology www.hemospat.com/terminology/index.php , 09/12/12